So-called intracranial germ cell tumours: personal experiences and a theory of their pathogenesis

We investigated 110 cases of intracranial germ cell tumours (up to the end of 1986), 56% of which showed monotypic histological patterns and 44% were shown to be mixed tumours. All these cases underwent surgery followed by radiation and/or chemotherapy. All cases of choriocarcinoma and embryonal carcinoma died within 2 yr: cases of endodermal sinus tumour also showed poor results (4 yr survival rate was 12.5%). Mature teratoma had a 5 yr survival rate (5YSR) and a 10 yr survival rate (10YSR) of 78.3% each: immature teratoma showed a 5YSR of 44.9%. Two-cell pattern tumours (PTC) showed a 5YSR of 85.8% and a 10YSR of 82.4%. They (PTC) can be divided into two groups (i) germinoma and (ii) pinealoma of pineal parenchyma origin (pineocytoma with lymphocytic infiltration) on the basis of the difference in the tumour cell-stroma relationship and also placental alkaline phosphatase stain. In the pineal region, 70% of PTC belonged to the category of pinealoma and in the suprasellar region, 92% of PTC were germinoma. Germinoma showed a 5YSR of 91.4% and a 10YSR of 91.4%, whereas those of the pinealoma were 78.2% and 68.4% respectively. This suggests that the biological characteristics of germinoma and pinealoma may be different. All these results may bring into question the validity of the germ cell theory, since germinoma, which should be the most undifferentiated according to the theory, was the most benign and choriocarcinoma and endodermal sinus tumour, which should be the most differentiated, were the most malignant in the follow-up study.(ABSTRACT TRUNCATED AT 250 WORDS)     

Radioimmunoassay of alpha-fetoprotein in children with primary intracranial tumors.

Serum alpha-fetoprotein (AFP) was measured in 10 cases of primary brain tumors in children (4 cases of medulloblastoma, 4 cases of germ cell tumor and 2 cases of astrocytoma). As a result, elevation in AFP was observed only in a case of embryonal carcinoma that showed partial mixture of germinoma. The absence of AFP elevation in 3 other cases of pure germinoma (atypical teratoma; pinealoma) agrees with reports which describe that, in the germ cell tumor of the gonads, a rise in AFP is not observed in pure seminoma but is found in embryonal carcinoma and endodermal sinus tumor (yolk sac tumor). The fluctuations in AFP in serum and cerebrospinal fluid are considered to be of significance in the diagnosis and treatment of primary intracranial malignant germ cell tumors.     

Electron microscopic study of an ectopic pinealoma

Summary A specimen from a patient with an ectopic pinealoma located in the third ventricle was investigated by light and electron microscopy.The study has demonstrated many small membrane-limited electron-dense granules in the pinealocyte-like principal tumor cells. They were similar to those found in the normal pineal body of mammals and probably represent granules of biogenic amines.The literature of biochemical studies on the secretion of the pineal body and the pinealoma was reviewed as supportive evidence of our ultrastructural findings.Research supported in part by Grant, NB-HD 06905-01 from the Public Healths Service, U.S. National Institutes of Health.     

Synaptic input to cochlear nucleus dendrites that receive medial olivocochlear synapses

Axons of olivocochlear neurons originate in the superior olivary complex and project to the cochlea. Along their course, medial olivocochlear axons give off branches to the cochlear nucleus. We labeled these branches with horseradish peroxidase and used electron microscopy to determine their target dendrites. Target dendrites were of two classes: “large” dendrites and “varicose” dendrites. Using serial sections, we reconstructed the dendrites and, in addition to the labeled olivocochlear input, we determined the synaptic profile of unlabeled inputs onto the dendrites. We classified the terminals on the basis of the shape and size of their synaptic vesicles. On large dendrites, the predominant type of unlabeled terminal had small round (SmRnd) vesicles. These terminals are likely to be excitatory, and some of them may originate from unlabeled medial olivocochlear branches. On varicose dendrites, the predominant type of terminal had pleomorphic vesicles. These terminals are likely to be inhibitory. They may be from descending inputs that arise in higher centers. A final type of terminal onto large dendrites exhibited signs of neuronal degeneration, possibly because the cell body of origin was damaged during the injection procedure. These terminals often had long, perforated synaptic densities and may originate from type II primary afferents. Thus, medial olivocochlear efferents and type II afferents, which both contact outer hair cells in the periphery, appear to synapse onto the same targets in the cochlear nucleus. In contrast, where examined, the target dendrites did not receive terminals with large vesicles from afferents that contact inner hair cells. Thus, target neurons appear to function in a neural circuit associated more closely with outer than with inner hair cells. © 1996 Wiley-Liss, Inc.     

Astrocytic cell clones derived from established cultures of 8-day postnatal mouse cerebella

Clonal permanent cell lines with astrocytic properties have been established from explant cultures of 8-day postnatal mouse cerebella after in vitro spontaneous transformation, i.e. without the addition of carcinogens or oncogenic viruses. The cell lines were derived in a multistage process. Slowly proliferating foci with several morphologies appeared 4 months after initiation of the cultures and became progressively enriched by cells with a homogeneous appearance. These cells could be established into permanent cell lines from which many clones were obtained. Some of these cloned cell lines bound anti-GFAP sera and therefore appeared to be astrocytic. According to their morphology, 3 separate types of these GFAP-positive clones could be distinguished. Type I and II cells had small somata; type I had several short processes, while type II had two processes, one of which was very thin and long ( 200 μm). Type III cells had large flat somata and no processes. The three types of clonal cell lines were labeled by monoclonal antibodies which bind to astrocytes in vivo. In particular, three monoclonal antibodies (BSP-3, M2 and M3) bound only to type II cells in a distinct pattern. Type I and II astrocytes are pseudodiploid and type III, heteroploid. The properties of these different clonal cell lines are very stable. We have thus obtained permanently established clonal cultures of mouse cerebellum astrocyte-like cells, which might be the in vitro counterparts of fibrous (type I), or velamentous (type III) astrocytes and of Golgi epithelial cells (type II).     

Are cranial germ cell tumours really tumours of germ cells?

Germ cell tumours of the brain and those that occur in the gonads are believed to share a common origin from germ cell progenitors. This 'germ cell theory' rests upon similar histopathology between these tumours in different locations and the belief that endogenous somatic cells of the brain could not give rise to the range of cell types seen in germ cell tumours. An alternative 'embryonic cell theory' has been proposed for some classes of cranial germ cell tumours, but this still relies on the misplacement of cells in the brain (in this case the earliest embryonic stem cells) during early embryonic development. Recent evidence has demonstrated that neural stem cells of the brain can also give rise to many of the cell types seen in germ cell tumours. These data suggest that endogenous progenitor cells of the brain are a plausible alternative origin for these tumours. This idea is of central importance for studies aiming to elucidate the mechanisms of tumour development. The application of modern molecular analyses to reveal how tumour cells have altered with respect to their cell of origin relies on the certain identification of the cell from which the particular tumour arose. If the identity of this cell is mistaken, then studies to elucidate the mechanisms by which the progenitor cell has been subverted from its normal behaviour will not yield useful information. In addition, it will prove impossible to generate an appropriate animal model in which to study the underlying causes of those tumours. This article makes the case that current assumptions of the origins of cranial germ cell tumours are unreliable. It reviews the evidence in favour of the 'germ cell theory' and argues in favour of a 'brain cell theory' in which endogenous neural progenitor cells of the brain are the likely origin for these tumours. Thus, the case is made that cranial germ cell tumours, like other brain tumours, arise by the transformation of progenitor cells normally resident in the brain.     

Pathophysiological mechanism of ipsilateral cerebral and brainstem hemiatrophy in basal ganglia germ cell tumors: case report

Introduction  The basal ganglia is an uncommon location for germ cell tumors. It has been reported that basal ganglia germinomas and mixed germ cell tumors are associated with ipsilateral cerebral and brainstem hemiatrophy on presentation. Several pathophysiological mechanisms including autoimmune process and direct tumor infiltration of the thalamus or the internal capsule have been postulated to explain this association. Case reports  The authors report two boys, aged 7 and 10, with basal ganglia germ cell tumors. Both of them presented with gradual onset of hemiparesis and had features of ipsilateral cerebral and brainstem hemiatrophy on imaging studies. They underwent chemotherapy followed by reduced dose radiotherapy with good response. Discussion  Pathophysiological mechanisms of the associated ipsilateral cerebral and brainstem hemiatrophy are discussed. The authors postulate that the gradual obliteration of the perforating arteries to the diencephalon especially the lenticulostriate arteries of the prebifurcation middle cerebral artery may be the major mechanism of the associated hemiatrophy.     

Ultrastructure of the ganglion cells of the terminal nerve in the dwarf gourami (Colisa lalia)

In our previous light microscopic studies (Oka et al., Brain Res. 367: 341-345, '86; Oka and Ichikawa, J. Comp. Neurol. 300: 511-522, '90), we reported that there are at least two types of terminal nerve (TN) cells based on cell size and immunoreactivity: type I cells had large cell bodies, while type II cells had smaller cell bodies. Type I TN cells were immunoreactive to gonadotropin-releasing hormone (GnRH) and may be the major source of GnRH-immunoreactive fibers that are widely distributed throughout the brain. Type II TN cells, on the other hand, were not immunoreactive to GnRH. In the present paper, we examined the cytology and synaptology of these two types of TN cells with electron microscopy. Type I TN cell bodies were found to have morphological characteristics similar to those of other peptide-synthesizing neurons and are likely to be actively synthesizing GnRH. The frequent occurrence of coated vesicles close to the plasma membrane of the cell body was suggestive of membrane retrieval following exocytosis of the vesicular contents from the cell surface. Neighboring TN cells were either in direct juxtaposition with one another or made specialized "glomeruloid" cell-to-cell contacts; these specializations may be relevant for nonsynaptic intercellular communications among the TN cells. Within these glomeruloid complexes, the somatic processes of TN cells received inputs from two types of synaptic terminals: one containing only spherical synaptic vesicles and another containing a small number of dense-cored vesicles in addition to the spherical synaptic vesicles. Axosomatic synapses were rare on type I TN cell bodies. In contrast, type II TN cell bodies had morphological characteristics similar to those of neurons in other brain regions. These receive axosomatic inputs from synaptic terminals containing only spherical synaptic vesicles and those with a small number of dense-cored vesicles in addition to the spherical synaptic vesicles. Thus, each type of TN cell has unique fine structural characteristics which may correlate to their different functional roles.     

Histochemistry with Helix pomatia agglutinin in human germ cell tumors: detection of nongerminomatous components and correlation between HPA reactivity and radiosensitivity in germinomas

Binding sites of Helix pomatia agglutinin (HPA) were examined in 32 patients with intracranial human germ cell tumors. HPA reactivity was found in vascular endothelial cells and erythrocytes of patients with blood type A or AB. HPA-positive neoplastic cells were seen in one yolk sac carcinoma in a patient with blood group. A, and in embryonal carcinomas and teratomas irrespective of blood group type. Although in 10 out of 18 germinomas neoplastic cells were totally negative for HPA, another 8 germinomas showed HPA-positive neoplastic cells which were distributed sporadically or in an area and independent of blood group types. HPA-negative germinoma patients showed a very good response to radiotherapy, whereas 4 out of 8 HPA-positive tumors showed poor radiosensitivity, with a residual lesion seen on computed tomography even after the total radiation dose of 40–50 Gy. These findings suggest that HPA-positive neoplastic cells in germinomas indicate components of differentiation of non-germinomatous germ cells. HPA-positive germinomas might be less radiosensitive than HPA-negative germinomas.     

Topography of cholinergic perikarya and nerve fibres as well as cholinergic vesicles in the rat duodenum

Using the acetylthiocholine staining method, it was possible to visualize acetylcholinesterase (AChE)-stained neuronal cell bodies and nerve endings as well as AChE-positive vesicles in the rat duodenum. AChE-reactive perikarya were seen with certainty only in the myenteric plexus. They were 40 μm in diameter and were mostly localized in groups within the ganglia (3–6 neurons per ganglion). Some thick, AChE-reactive nerve processes, running over a long distance in interconnecting nerve fibre strands, had their origin from AChE-containing myenteric plexus perikarya. AChE-stained nerve fibres were detected in the myenteric and submucosal plexus as well as in the longitudinal and circular smooth muscle cell layer. AChE-positive nerve fibres were in close contacts with blood vessels, probably arterioles, Brunner's gland cells and epithelial cells. A conspicuously high density of AChE-positive nerve fibres was noted in the longitudinal smooth muscle layer, while AChE-stained nerve fibres were visualized only sporadically in the circular smooth muscle layer. Some Brunner's gland cells and epithelial cells contained AChE-reactive vesicles, which were constantly localized on the basal cell portion. The present findings might indicate that acetylcholine possesses important physiological roles as neurotransmitter and/or neuromodulator in the rat duodenum.     

Cerebellar ganglioglioma in a child.

A cerebellar ganglioglioma was surgically removed from a two-year old boy, who had developed manifestations of increased intracranial pressure and cerebellar symptoms. At surgery, the tumor presented as a firm nodular mass displacing the cerebellar cortex. By light microscopy, its architecture differed distinctly from that of hamartomatous diffuse hypertrophy of the cerebellar cortex (Lhermitte-Duclos' disease). Mature ganglion cells were grouped in clusters and linked by thick bundles of nerve cell processes. Nerve cells and processes were enmeshed in a rich network of fibrillary connective tissue. Electron microscopy disclosed typical neuronal perikarya as well as numerous asymmetric chemical synapses. The bulk of the tumor consisted of tightly grouped, (non-myelinated) nerve cell processes arranged in parallel. One of the most prominent features of the tumor consisted of numerous dilatations of these processes. The largest ones contained microfilaments, while the smaller ones were entirely filled with dense bodies (most probably derived from degenerating mitochondria). Only scattered dense core vesicles were seen, which probably did not represent neurosecretory granules. A second cell type consisted probably of astrocytes. Most neuroepithelial cell processes could not be identified with certainty as being of either neuronal or glial origin. A third cell type consisted of numerous slender cells which were probably mesenchymal. They were surrounded by a network of basement membrane which extended between the surrounding nerve cell processes.     

HCG proved by enzyme labelled antibody technique in a suprasellar tumour--an autopsy case report (author's transl)]

An 11-year-old female case of suprasellar tumour was reported. She presented consciousness disorder without precocious puberty. Microscopically, two cell pattern pinealoma and choriocarcinoma with no metastasis were revealed. By means of enzyme-labelled antibody technique, the authors proved HCG in syncytial cells of the tumour.     

The inhibitory effect of aspirin on human endothelial cells.

Human endothelial cell monolayers prepared from umbilical veins have been incubated with aspirin (1--2 mM) dissolved in Hepes modified solution and in platelet-rich plasma. They have also been incubated with plasma prepared from subjects before and after intake of aspirin giving a mean plasma concentration of 0.5 mM. The effects of the endothelial cells on ADP and collagen-induced platelet aggregation and malondialdehyde production in platelet-rich plasma have been tested. The endothelial cells had a spontaneous inhibitory effect on all three parameters. This effect was abolished when the cells were incubated with aspirin dissolved in MHS for 20 min and the increase in effect observed when platelet-rich plasma was incubated with endothelial cells for a period of 30 min was similarly inhibited when aspirin was dissolved in plasma or when plasma prepared from subjects who had taken aspirin were used. Aspirin had no inhibitory effect on prostacyclin (PGI2) with regard to the effect of PGI2 on platelets. On the contrary, the two compounds had an additive inhibitory effect on platelet aggregation induced by ADP and collagen. These findings should be considered with regard to the use of aspirin as an antithrombotic agent.     

Cell configurations in the olfactory tubercle of the rat

The rat olfactory tubercle was studied with the rapid Golgi method. Several distinct cell types were identified mainly on the basis of the size of their somata and the structure of their dendrites. The commonest neuron type in the tubercle is the medium-sized densely spined cell. The somata of these neurons occur chiefly in the dense cell and multiform layers. They also form the cell bridges that directly link the olfactory tubercle with the nucleus accumbens and caudate-putamen. Their dendritic trees exhibit a variety of shapes; some of them are spherical, some are bipolar, and others are asymmetrical. The axons project dorsally, deep into the multiform layer. En route they give off numerous collaterals. A large version of this cell type is the crescent cell. Other medium-sized neurons also have somata in the dense cell and multiform layers. They include the spindle cells, so named because of the shape of their cell bodies, and the medium-sized spine-poor neurons. Neither of these cell types has dendritic trees that are as highly branched as those of the medium-sized densely spined cells. There are three types of small cells; their somata occur primarily in the dense cell and molecular layers. The dwarf cells are near the pial surface, although their somata are included in the dense cell layer, and they have axons that resemble those of medium-sized densely spined cells. The radiate cells have numerous, relatively short, spine-free dendrites that extend out from the rounded somata in all directions. The small spine-rich cells look like miniature versions of the medium-sized densely spined neurons. They are frequently confined to the molecular layer. Large spine-poor neurons, with their cell bodies located in the dense cell and multiform layers, seem to be a heterogeneous cell group since there are subtle variations in the structure of their dendrites and the shape and extent of their dendritic trees. The large, moderately spined neurons are less common than the other large cells; their somata are found in all three layers. The granule cells of the islands of Calleja make up the most homogeneous cell group. They have only a few dendrites, and these are quite thin. Except for the medium-sized densely spined and dwarf cells, the axons of the different cell types were not very well impregnated. The different cell types in the tubercle are compared to cells in the nucleus accumbens, caudate-putamen, and globus pallidus.(ABSTRACT TRUNCATED AT 400 WORDS)     

Muscle and nerve changes induced by perhexiline maleate in man and mice

Perhexiline maleate therapy may produce a polyneuropathy as well as other side effects in man. The Schwann-cell origin of the neuropathy is demonstrated by morphologic studies. Ultrastructural studies of muscle and nerve biopsies showed the presence of intracytoplasmic inclusions, primarily in Schwann cells, muscle fibers, and endothelial cells. These inclusions were polymorphic and varied from one cell type to another. They were frequently associated with calcium deposits, and their structure suggested a lysosomal origin. It was possible experimentally to reproduce similar inclusions in mice. Furthermore, numerous tubular aggregates were observed in intoxicated mouse muscle fibers.     

Bovine normal peripheral nerve and nerve sheath tumour in explant culture

Summary When bovine normal nerve and nerve sheath tumours were cultured using explant techniques, the same morphological cell types were seen: thin bipolar cells with bulging nuclei; round refractile cells; large quadrangular cells; variable polar, wide-processed cells. However, differences in the pattern of cell growth and the proportions of morphological cell types occurred between normal and tumour nerve.The bovine nerve sheath tumours cultured showed a range of histological areas which did not appear to affect the pattern of cell growth in culture or the cell types present. Antoni type A tissue was prominent in many explant blocks and probably gave rise to most cell growth.On comparison with human schwannomas maintained in explant culture, bovine nerve sheath tumours appeared to have a similar range of morphological cell types. Although suggestions for the origin of human schwannomas have been made on the basis of cell morphology, it was felt that morphology alone did not allow speculation on the origin of cells present in bovine nerve sheath tumour explant cell growth.This work was supported by grants from the Australian Meat Research Committee, the George Aitken Pastoral Trust and the Cancer Research Committee of the University of Sydney     

Two discrete enkephalinergic neuron systems in the superior cervical ganglion of the guinea pig: an immunoelectron microscopic study

Leucine-enkephalin (L-ENK)-like immunoreactive (L-ENKI) structures in the superior cervical ganglion (SCG) were first examined by using immunoelectron microscopy. L-ENKI neurons formed cell clusters and were small. They were filled with large granular or agranular vesicles and small electron lucent vesicles, and had nuclei that lacked a nucleolus. Since these morphological characteristics are identical to those of the small intensely fluorescent (SIF) cells, L-ENKI cells seemed to be a kind of SIF cell. Two types of L-ENKI fibers were identified, a large type filled with large granular or agranular vesicles and a small type filled with small electron lucent vesicles. The large fibers were located near the L-ENKI perikarya and often could be traced directly to the soma. These fibers remained intact after decentralization of the SCG. These findings indicate that the large L-ENKI fibers are processes of L-ENKI SIF cells. The fibers showed a close apposition to the blood vessels and rarely formed synaptic contact with dendrites of the principal cells. On the other hand, the small L-ENKI fibers were found to originate outside the SCG, because they disappeared after decentralization of the SCG. These L-ENKI fibers frequently formed synaptic contact with the dendrites of the principal cells. Thus, the present study demonstrated the presence of two discrete L-ENKI neuron systems in the SCG of the guinea pig, one an intrinsic SIF system and the other an extrinsic L-ENKI system.     

Establishment and characteristics of a practical and useful astrocyte cell line transformed by a temperature-sensitive mutant of simian virus 40

A practical mouse astrocyte cell line (A640-IG) was established by transformation with a temperature-sensitive mutant of simian virus 40 (SV40) and the relationship between the function of SV40 large T antigen and the growth and differentiation of A640-IG cells, which are most clearly dependent on temperature that ever established, was reported. A640-IG cells proliferated actively with expression of large T antigen when they were cultured at 33°C. They had a fibroblast-like appearance, and displayed faint immunoreactivity with an antibody against glial fibrillary acidic protein (GFAP). However, when large T antigen expression ceased at 39°C, the cells did not grow actively and differentiated into astrocytes as demonstrated by both their morphological and immunohistochemical characteristics. Differentiation into astrocytes was more obvious when the cells were plated on bacteriological dishes in high density. Western blotting confirmed immunohistochemical observations. A640-IG cells thus showed contrasting behaviour in terms of cell growth and differentiation depending on the temperature. This unique and practical astrocyte cell line is a useful model for investigating the mechanisms of astrocyte growth and differentiation.     

Ultrastruktur einer Kolloidcyste des dritten Ventrikels

Summary The histology and ultrastructure of a third ventricle colloid cyst, successfully removed from a 43 year old female, is described. The cyst had caused signs of increased intracranial pressure. Three different epithelial cell types can be differentiated in light and electron microscopy. Ciliated epithelial cells are most frequent. Their apical surface is occupied by numerous cilia and microvilli. The second cell typ produces mucine. The cells bear club shaped processes which extend into the cyst cavity. The electron micrographs suggest an apocrine type of secretion. The third cell type contains PAS-positive granules. The cells accumulate the secretory products in their interior. The whole cell is thereafter expelled into the cyst. This type of secretion has to be called holocrine. The origin of the colloid cysts is discussed.

     

Maintenance of immunocytologically identified Purkinje cells from mouse cerebellum in monolayer culture

Purkinje cells were identified in monolayer cultures obtained from trypsin-dissociated cerebella of embryonic and early postnatal mice by the Purkinje cell-specific monoclonal antibodies PC1, PC2, PC3 and UCHT1. These cells also expressed the neuronal marker L1 antigen but not the glial markers, glial fibrillary acidic protein or 04 antigen. They also expressed tetanus toxin receptors, PC4, M1 and Thy-1 antigens. Survival of Purkinje cells was best: (a) when cerebella were taken from mice not older than one day of age: (b) when cells were seeded at higher plating densities; and (c) cultured in chemically defined medium which facilitates the survival of neurons. No Purkinje cells could be detected in cultures from mice older than 6 days. PC1 antigen expression developed in vitro on the same time scale as in vivo, i.e. it was first detectable at the equivalent of postnatal days 3–4. At this stage cell bodies had a size of 13–14 μm in diameter and few processes. Dendrite-like arborizations, with more than one primary dendrite, extension of usually only one thin and long (0.5–1.6 mm) axon-like process and collaterals directed preferentially towards other Purkinje cells, developed with time in culture until the final form was reached by the equivalent of approximately day 16. Cell body size was 18–19 μm in diameter at this stage. Cell shapes were reminiscent of those described in certain cerebellar mouse mutants and in experimentally produced agranular cerebella. Many ultrastructural features of these cells correlated with those described for the in vivo counterpart. However, there was a lack of spiny branchlets and abnormally long persisting somatic spines. Synaptic contacts of the ‘en passant’ type could be seen at the Purkinje cell soma. Gray type I synapses were seen on Purkinje cell dendrites and spines.